IB is a highly infectious/transmissible respiratory disease that affects chickens of all ages. The disease of IB is caused by a virus of the coronavirus group. IB disease symptoms vary widely; however, reported effects include death, respiratory tract distress, depressed production, decreased peak production of eggs, abnormalities in the eggshells, diarrhea, and a nephrosis/nephritis syndrome. Undesired weight loss in young chicks and/or insufficient/low-quality production of eggs from laying flocks are commercially-significant adverse impacts of IB disease in chickens.
Commercially-available vaccines for IB are not administered in ovo. Rather, they are administered post-hatch in a variety of formats. Briefly, such vaccines are typically administered by the labor-intensive methods of spraying (e.g., hand spray, knapsack spray, or automated spray equipment) or in drops (eye or nose).
As more fully explained below, the in ovo vaccines of the present invention provide distinctive advantages over the inconvenient and time-consuming post-hatch routes of administration presently available.